Stomatopods as Pests

The following methods of control were compiled from various sources around the web, and so the author of this site does not give any guarantees on the efficacy of any of the techniques.

Methods for Capturing Within the Tank:

Use live bait to lure it out, then use nets to capture it. This is the simplest technique, and yet may be the least reliable, especially given the keen eyesight and quickness of many of the smaller mantis shrimps. Also, I find them to be extremely cautious creatures, and if there are hiding places around, it will be very difficult to catch them unawares and vulnerable to simple nets.
Use home-made traps to capture the mantis shrimp. One enterprising soul made a funnel-type apparatus by cutting out the top half of a small clear plastic bottle close to where the gradual slope turns to a straight line. He then inserted the top part into the lower half in an inverted position, and secured the whole apparatus by tying a fishing line around the neck of the top half and through a hole in the bottom. A piece of shrimp was secured inside the trap to serve as bait.
Here's a page with a similar home-made trap:
http://www.geocities.com/CapeCanaveral/Hangar/6279/LettersMantisShrimp.html
A menagerie of home-made traps (external link!).
Use commercial traps.
The Prairie Dog "Suction" Method
- This is surely one of the more novel methods of capturing mantis shrimps, and involves the use of a suction to trap the critter. The exact location of the mantis shrimp's home cavity must first be determined, and the hose of a strong filter is then secured tightly over the hole. The system is left to run overnight, and the stomatopod is invariably found trapped inside the filter when morning comes. The contributor has been successful all three times he used this method, and has the stomatopod "trophies" on his wall to prove it. In order to work, the mantis shrimp must be of a manageable size, the location of its hole must be precisely determined, and there must not be any other escape routes within the rock.
The Scissor Method
- If you've got the reflexes and "guts" to go mano a mano against the mantis shrimps, then this is for you. On the serious side, I would caution that mantis shrimps display a relatively high degree of behavioral plasticity, and the very aggressive behavior of the mantis in the story may not be applicable to other mantis individuals. For example, the large mantises I maintain do not charge out when I start poking into the insides of their cavities. Instead, they just keep hammering at the intruding object.
Use competing animals to control or remove the mantis shrimp. This is much more troublesome and less reliable than using traps, and may involve the temporary removal of other inhabitants out of the container. Unless the competing creature is significantly larger than the mantis shrimp, there's every chance that you're going to lose it instead. These are not recommended methods for mantis shrimp removal.
1. Trigger fishes- you will need to make sure all the other remaining inhabitants are compatible with the trigger you use (much larger or with a very dissimilar shape), or else remove all other potential snacks before introducing undulate triggers or the like. Although this is a relatively common method of getting rid of the smaller mantis shrimps (LFS regularly drop their "dazed" caught stomatopods -- frequently the very small Gonodactylus spp, into Triggerfish tanks), larger critters are another matter entirely. Large Odontodactylus scyllarus, for example, will be able to handle these fishes with ease......according to Dr. Roy Caldwell, a wholesaler once offered him a couple of Odontodactylus scyllarus after they had killed 6 Clown Triggers in a single night.
2. Octopuses- remove potential prey, then introduce borrowed, rented, or bought octopus into tank. Make sure there are no relatively large openings or the thing will easily escape and wander around your kitchen at night in search of food. The size thing goes here as well. Large mantis shrimps will gladly eat smaller octopi.
3. Pistol shrimps- these clicking shrimps supposedly compete for cavities with the mantis shrimps. The good thing about using these animals is that they are relatively harmless to other inhabitants of the tank, unlike the two above. The bad thing is that I very much doubt this will work. I've seen pistols jostling against other pistols in TV, and their claws do seem to be effective weapons. But I've also seen mantis shrimps easily handle large crayfishes, who sport equally massive pincers, and these contests weren't even close.
4. Sally Lightfoot Crabs- someone mentioned this in a newsgroup, someone disagreed. I would bet on the mantis if they were around the same size (heck, i would bet on the mantis if the crab were twice its size).
5. Hawk Fishes- maybe, maybe not. An aquarist in a ng reported that a 3 inch fish ate a 1.5 inch mantis shrimp, although he did not actually see the thing happening.
6. A reader mentioned that Moray Eels with molar like teath such as the Snowflake or Zebra moray will eliminate stray mantis shrimp within a week. He keeps a pair of snowflakes in the curing tank and notes that he has never gotten any mantis shrimp on the rock after curing.

Methods to Capture Mantis Shrimp Outside Tank:

If you can quickly remove the rock where the offending mantis shrimp is hiding, then you can isolate the animal using the following methods.

Replace rock in its own, isolated tank with saltwater. Do not provide sources of food for several days, then trap mantis using bait.
Dunk rock quickly in carbonated water. You may use club soda or make your own liquid by mixing dry ice and saltwater. The mantis shrimp will quickly scoot out of the rock when exposed to this.
Squirt boiling or hot water into the cavities where mantis shrimps may be hiding. This has been suggested to me by retailers of local fishing stores as well.
Dunk rock in freshwater. Some people say they have used this to good effect, but others note that it could severely damage the other inhabitants of the live rock.